Some Infertile Men Show Higher Cancer Risk: Study
Factors that contribute to lack of sperm may also raise odds for tumors, researchers say
And some of those genetic flaws might be involved in cancer susceptibility, he said.
Another infertility expert was cautious about interpreting the findings because of the small numbers: only 10 cases of cancer among the 451 men with azoospermia, and 19 cases among nearly 1,800 men with other types of infertility.
The idea that genetic abnormalities might underlie both azoospermia and cancer risk has merit, said Dr. Frederick Licciardi of NYU Langone Medical Center in New York City. But, he said, "while this is important reasoning and is based in basic science studies, I do not feel they have enough evidence in this paper to bolster this theory."
Another question is whether azoospermia is linked only to certain cancers. Past studies, including one Walsh worked on, have found that infertile men show a higher than average risk of testicular cancer -- a highly curable disease usually diagnosed in young men.
Of the 10 cancers in azoospermic men in this study, two were testicular tumors. The others included brain cancer, prostate cancer, lymphoma and melanoma.
Eisenberg said there were too few cases of each cancer to see whether men with azoospermia were at particular risk for any one type.
For now, he recommended that men with the condition "be aware of the possible risk, and pay attention to your health." That includes not only maintaining a healthy lifestyle, he said, but also doing what most younger men do not -- seeing your doctor for a regular check-up.
"It's too early to make any recommendations about cancer screening," he said. But a routine visit to your doctor for a physical exam -- which can detect testicular cancer, for example -- is wise, Eisenberg said.
Licciardi agreed. "Any man -- very low sperm count or not -- should have regular physical examinations."
Walsh said much more research is needed to dig into the connection between male infertility and cancer, including studies that follow men over a long period since cancer rates climb with age, as well as basic lab research to try to uncover the reasons for the link.